Add support for Western Armenian (hyw)

was rejected in the early years, but with the help of adopted 2017-023 request, it's now enabled

As per langcom discussion on WMCON, the code hyw will be requested for w:Western_Armenian and we are sure it will be approved, but only at the earliest in December. But the users would already like to translate into it. Pinging user:Raymond.

The language name in English and in its own language (for example 'German – Deutsch (de)') - Western Armenian - արեւմտահայերէն

Is the language RTL or LTR (written from right to left or left to right) - LTR

If the language is commonly written in more than one script, please say in which script the language should be enabled. Other variants can be enabled as and when translators for those variants volunteer. - Armn only

(For MediaWiki) Should the language fall back to another language other than English? If so which? - Fallback should be to hy.